U.S. patent number 10,545,598 [Application Number 15/540,348] was granted by the patent office on 2020-01-28 for display panel, pressure sensitive touch screen, and display device.
This patent grant is currently assigned to BEIJING BOE OPTOELECTRONICS TECHNOLOGY CO., LTD., BOE TECHNOLOGY GROUP CO., LTD.. The grantee listed for this patent is BEIJING BOE OPTOELECTRONICS TECHNOLOGY CO., LTD., BOE TECHNOLOGY GROUP CO., LTD.. Invention is credited to Xiaochuan Chen, Xiaoliang Ding, Xue Dong, Yingming Liu, Pengcheng Lu, Haisheng Wang, Lei Wang, Rui Xu, Hailin Xue, Ming Yang, Shengji Yang.
United States Patent |
10,545,598 |
Yang , et al. |
January 28, 2020 |
Display panel, pressure sensitive touch screen, and display
device
Abstract
A display panel, a pressure sensitive touch screen, and a
display device are disclosed. Pressure sensitive touch structures
are arranged between an array substrate and a counter substrate.
Each pressure sensitive touch structure includes a first touch
electrode, a piezoelectric conversion layer, and a second touch
electrode. In case each pressure sensitive touch structure is
subject to a pressure, the pressure sensing unit determines the
magnitude of pressure at the touch position by sensing a variation
in the magnitude of voltage between the first touch electrode and
the second touch electrode, thus realizing pressure touching. Since
the pressure sensitive touch structures are embedded in the display
panel, it is only required to make minor modification to the
structural design of the display panel without being limited by the
assembly tolerance. The detection accuracy is improved.
Inventors: |
Yang; Shengji (Beijing,
CN), Dong; Xue (Beijing, CN), Xue;
Hailin (Beijing, CN), Chen; Xiaochuan (Beijing,
CN), Wang; Haisheng (Beijing, CN), Liu;
Yingming (Beijing, CN), Ding; Xiaoliang (Beijing,
CN), Xu; Rui (Beijing, CN), Wang; Lei
(Beijing, CN), Yang; Ming (Beijing, CN),
Lu; Pengcheng (Beijing, CN) |
Applicant: |
Name |
City |
State |
Country |
Type |
BOE TECHNOLOGY GROUP CO., LTD.
BEIJING BOE OPTOELECTRONICS TECHNOLOGY CO., LTD. |
Beijing
Beijing |
N/A
N/A |
CN
CN |
|
|
Assignee: |
BOE TECHNOLOGY GROUP CO., LTD.
(Beijing, CN)
BEIJING BOE OPTOELECTRONICS TECHNOLOGY CO., LTD. (Beijing,
CN)
|
Family
ID: |
56467150 |
Appl.
No.: |
15/540,348 |
Filed: |
May 11, 2016 |
PCT
Filed: |
May 11, 2016 |
PCT No.: |
PCT/CN2016/081686 |
371(c)(1),(2),(4) Date: |
June 28, 2017 |
PCT
Pub. No.: |
WO2017/152485 |
PCT
Pub. Date: |
September 14, 2017 |
Prior Publication Data
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|
|
|
Document
Identifier |
Publication Date |
|
US 20180181247 A1 |
Jun 28, 2018 |
|
Foreign Application Priority Data
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|
|
|
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Mar 10, 2016 [CN] |
|
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2016 1 0136567 |
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
G06F
3/0416 (20130101); G06F 3/0414 (20130101); G06F
3/04144 (20190501); G06F 3/041 (20130101); G06F
3/0412 (20130101); H01L 41/1132 (20130101); H01L
27/1255 (20130101); G06F 2203/04105 (20130101) |
Current International
Class: |
G06F
3/041 (20060101); H01L 27/12 (20060101); H01L
41/113 (20060101) |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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102193225 |
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Sep 2011 |
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CN |
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102707470 |
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Oct 2012 |
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CN |
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104409473 |
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Mar 2015 |
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CN |
|
105117058 |
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Dec 2015 |
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CN |
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205038626 |
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Feb 2016 |
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CN |
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105373228 |
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Mar 2016 |
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CN |
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Other References
Search Report for International Application No. PCT/CN2016/081686
dated Nov. 28, 2016. cited by applicant .
First Office Action for Chinese Patent Application No.
201610136567.0 dated Feb. 2, 2018. cited by applicant.
|
Primary Examiner: Lamb; Christopher R
Attorney, Agent or Firm: Calfee, Halter & Griswold
LLP
Claims
What is claimed is:
1. A display panel, comprising: an array substrate, a counter
substrate opposite to the array substrate, and a plurality of pixel
units which are arranged in a matrix between the array substrate
and the counter substrate, wherein the display panel further
comprises a plurality of pressure sensitive touch structures
between the array substrate and the counter substrate, wherein each
of the pressure sensitive touch structures comprises a first touch
electrode, a piezoelectric conversion layer, and a second touch
electrode which are arranged in this order on a side of the array
substrate facing the counter substrate, wherein the display panel
further comprises pressure sensing units, each of the pressure
sensing units is electrically connected to each of the pressure
sensitive touch structures, wherein each of the pressure sensing
units is configured to determine the magnitude of pressure at the
touch position, by sensing a variation in the magnitude of voltage
between the first touch electrode and the second touch electrode
during the pressure touching stage, wherein each of the pressure
sensing units comprises a pressure sensing circuit and a pressure
determining circuit wherein the pressure sensing circuit and the
pressure determining circuit correspond to each of the pressure
sensitive touch structures, the pressure sensing circuit is
configured to amplify the voltage of the corresponding pressure
sensitive touch structure and to output the amplified voltage, and
the pressure determining circuit is configured to determine the
magnitude of pressure at the touch position according to the
voltage output by the pressure sensing circuit, and wherein the
pressure sensing circuit comprises a switch transistor, a first
capacitor, and an amplifying transistor, the switch transistor
comprises a first gate connected with a reset control terminal, a
first source connected with a reset signal terminal, and a first
drain connected with a first terminal of the first capacitor and
the first touch electrode of the corresponding pressure sensitive
touch structure, a second terminal of the first capacitor is
connected with a first reference signal terminal, and the
amplifying transistor comprises a second gate connected with the
first terminal of the first capacitor, a second source connected
with a second reference signal terminal, and a second drain
connected with the pressure determining circuit.
2. The display panel of claim 1, wherein each of the plurality of
pixel units comprises a first conductive layer and a second
conductive layer which are arranged in this order on the array
substrate, and each of the plurality of pixel units further
comprises a light emitting layer arranged between the first
conductive layer and the second conductive layer, wherein the first
conductive layer is an anode layer, and the second conductive layer
is a cathode layer.
3. The display panel of claim 1, wherein each of the plurality of
pixel units comprises a first conductive layer and a second
conductive layer arranged in this order on the array substrate, and
each of the plurality of pixel units further comprises an
insulating layer arranged between the first conductive layer and
the second conductive layer, wherein the first conductive layer is
a pixel electrode layer, and the second conductive layer is a
common electrode layer.
4. The display panel of claim 2, wherein the second conductive
layer is multiplexed as the second touch electrode, and the first
touch electrode and the first conductive layer are arranged in a
same layer, made from a same material and insulated from each
other.
5. The display panel of claim 4, further comprising a black matrix
arranged between the array substrate and the counter substrate,
wherein an orthographic projection of the first touch electrode on
the array substrate falls within an orthographic projection of the
black matrix on the array substrate.
6. The display panel of claim 2, wherein the second touch electrode
and the first conductive layer are arranged in a same layer, made
from a same material and insulated from each other.
7. The display panel of claim 6, further comprising a black matrix
arranged between the array substrate and the counter, wherein an
orthographic projection of the second touch electrode on the array
substrate falls within an orthographic projection of the black
matrix on the array substrate.
8. The display panel of claim 1, wherein the pressure sensing
circuit further comprises an amplifier, a second capacitor, and a
switch device, the amplifier comprises a positive phase input
terminal which is connected with a third reference signal terminal,
a negative phase input terminal which is connected with a drain of
the amplifying transistor, and an output terminal which is
connected with the pressure determining circuit, the second
capacitor is connected between the negative phase input terminal
and the output terminal of the amplifier, and the switch device is
connected between the negative phase input terminal and the output
terminal of the amplifier.
9. The display panel of claim 1, wherein the piezoelectric
conversion layer comprises piezoelectric material.
10. A pressure sensitive touch screen, comprising a display panel,
the display panel comprises an array substrate, a counter substrate
opposite to the array substrate, and a plurality of pixel units
which are arranged in a matrix between the array substrate and the
counter substrate, wherein the display panel further comprises a
plurality of pressure sensitive touch structures between the array
substrate and the counter substrate, wherein each of the pressure
sensitive touch structures comprises a first touch electrode, a
piezoelectric conversion layer, and a second touch electrode which
are arranged in this order on a side of the array substrate facing
the counter substrate, wherein the pressure sensitive touch screen
further comprises pressure sensing units, each of the pressure
sensing units is electrically connected to each of the pressure
sensitive touch structures, wherein each of the pressure sensing
units is configured to determine the magnitude of pressure at the
touch position, by sensing a variation in the magnitude of voltage
between the first touch electrode and the second touch electrode
during the pressure touching stage, wherein each of the pressure
sensing units comprises a pressure sensing circuit and a pressure
determining circuit which correspond to each of the pressure
sensitive touch structures, the pressure sensing circuit is
configured to amplify the voltage of the corresponding pressure
sensitive touch structure and to output the amplified voltage, and
the pressure determining circuit is configured to determine the
magnitude of pressure at the touch position according to the
voltage output by the pressure sensing circuit, and wherein the
pressure sensing circuit comprises a switch transistor, a first
capacitor, and an amplifying transistor, the switch transistor
comprises a first gate connected with a reset control terminal, a
first source connected with a reset signal terminal, and a first
drain connected with a first terminal of the first capacitor and
the first touch electrode of the corresponding pressure sensitive
touch structure, a second terminal of the first capacitor is
connected with a first reference signal terminal, and the
amplifying transistor comprises a second gate connected with the
first terminal of the first capacitor, a second source connected
with a second reference signal terminal, and a second drain
connected with the pressure determining circuit.
11. The pressure sensitive touch screen of claim 10, wherein the
pressure sensing circuit further comprises an amplifier, a second
capacitor, and a switch device, the amplifier comprises a positive
phase input terminal connected with a third reference signal
terminal, a negative phase input terminal connected with a drain of
the amplifying transistor, and an output terminal connected with
the pressure determining circuit, the second capacitor is connected
between the negative phase input terminal and the output terminal
of the amplifier, and the switch device is connected between the
negative phase input terminal and the output terminal of the
amplifier.
12. A display device, comprising the pressure sensitive touch
screen of claim 10.
Description
RELATED APPLICATIONS
The present application is the U.S. national phase entry of
PCT/CN2016/081686, with an international filing date of May 11,
2016, which claims the benefit of Chinese Patent Application
201610136567.0, filed on Mar. 10, 2016, the entire disclosures of
which are incorporated herein by reference.
TECHNICAL FIELD
The present disclosure relates to the field of display technology,
and particularly to a display panel, a pressure sensitive touch
screen, and a display device.
BACKGROUND
A pressure sensing technique refers to a technique in which an
external force is detected, and has been applied to industrial
control, medical field, or the like. Currently, in the display
field, especially in the field of mobile phone or tablet computer,
additional structures are added in a backlight of a liquid crystal
display panel or a middle frame of a mobile phone to realize
pressure sensing. In this design, it is required to modify the
structural design of the liquid crystal display panel or mobile
phone. Furthermore, since the assembly tolerance is relatively
large, the detection accuracy of this design is limited.
Therefore, it is a pressing problem for an ordinary skilled person
in the art to realize pressure sensing at high detection accuracy
in the premise that minor physical modification is made to the
display panel.
SUMMARY
Embodiment of the present disclosure provide a display panel, a
pressure sensitive touch screen, and a display device, in which
pressure sensitive touch structures are embedded in the display
panel to realize the function of pressure touching. It is only
required to make minor modification to the structural design of the
display panel without being limited by the assembly tolerance, and
the detection accuracy is improved.
An embodiment of the present disclosure provides a display panel,
comprising: an array substrate, a counter substrate opposite to the
array substrate, and a plurality of pixel units which are arranged
in a matrix between the array substrate and the counter substrate,
wherein the display panel further comprises a plurality of pressure
sensitive touch structures between the array substrate and the
counter substrate, and wherein each of the pressure sensitive touch
structures comprises a first touch electrode, a piezoelectric
conversion layer, and a second touch electrode which are arranged
in this order on a side of the array substrate facing the counter
substrate.
In an exemplary embodiment, each of the plurality of pixel units
comprises a first conductive layer and a second conductive layer
which are arranged in this order on the array substrate. Each of
the plurality of pixel units further comprises a light emitting
layer which is arranged between the first conductive layer and the
second conductive layer, the first conductive layer is an anode
layer, and the second conductive layer is a cathode layer.
In an exemplary embodiment, each of the plurality of pixel units
comprises a first conductive layer and a second conductive layer
which are arranged in this order on the array substrate. Each of
the plurality of pixel units further comprises an insulating layer
which is arranged between the first conductive layer and the second
conductive layer, the first conductive layer is a pixel electrode
layer, and the second conductive layer is a common electrode
layer.
In an exemplary embodiment, the second conductive layer is
multiplexed as the second touch electrode, and the first touch
electrode and the first conductive layer are arranged in a same
layer, made from a same material and insulated from each other.
In an exemplary embodiment, the display panel further comprises a
black matrix which is arranged between the array substrate and the
counter substrate, wherein an orthographic projection of the first
touch electrode on the array substrate falls within an orthographic
projection of the black matrix on the array substrate.
In an exemplary embodiment, the second touch electrode and the
first conductive layer are arranged in a same layer, made from a
same material and insulated from each other.
In an exemplary embodiment, the display panel further comprises a
black matrix which is arranged between the array substrate and the
counter substrate, wherein an orthographic projection of the second
touch electrode on the array substrate falls within an orthographic
projection of the black matrix on the array substrate.
In an exemplary embodiment, the display panel further comprises
pressure sensing units, each of the pressure sensing units is
electrically connected to each of the pressure sensitive touch
structures, wherein each of the pressure sensing units is
configured to determine the magnitude of pressure at the touch
position, by sensing a variation in the magnitude of voltage
between the first touch electrode and the second touch electrode
during the pressure touching stage.
In an exemplary embodiment, each of the pressure sensing units
comprises a pressure sensing circuit and a pressure determining
circuit which correspond to each of the pressure sensitive touch
structures. The pressure sensing circuit is configured to amplify
the voltage of the corresponding pressure sensitive touch structure
and to output the amplified voltage. The pressure determining
circuit is configured to determine touch position magnitude of
pressure according to the voltage output by the pressure sensing
circuit.
In an exemplary embodiment, the pressure sensing circuit comprises
a switch transistor, a first capacitor, and an amplifying
transistor. The switch transistor comprises a gate which is
connected with a reset control terminal, a source which is
connected with a reset signal terminal, and a drain which is
connected with a first terminal of the first capacitor and the
first touch electrode of the corresponding pressure sensitive touch
structure. A second terminal of the first capacitor is connected
with a first reference signal terminal. The amplifying transistor
comprises a gate which is connected with the first terminal of the
first capacitor, a source which is connected with a second
reference signal terminal, and a drain which is connected with the
pressure determining circuit.
In an exemplary embodiment, the pressure sensing circuit comprises
a switch transistor, a first capacitor, and an amplifying
transistor. The switch transistor comprises a gate which is
connected with a reset control terminal, a source which is
connected with a reset signal terminal, and a drain which is
connected with a first terminal of the first capacitor and the
first touch electrode of the corresponding pressure sensitive touch
structure. A second terminal of the first capacitor is connected
with a first reference signal terminal. The amplifying transistor
comprises a gate which is connected with an amplifying control
terminal, a source which is connected with a first terminal of the
first capacitor, and a drain which is connected with the pressure
determining circuit.
In an exemplary embodiment, the pressure sensing circuit further
comprises an amplifier, a second capacitor, and a switch device.
The amplifier comprises a positive phase input terminal which is
connected with a third reference signal terminal, a negative phase
input terminal which is connected with a drain of the amplifying
transistor, and an output terminal which is connected with the
pressure determining circuit. The second capacitor is connected
between the negative phase input terminal and the output terminal
of the amplifier. The switch device is connected between the
negative phase input terminal and the output terminal of the
amplifier.
In an exemplary embodiment, the piezoelectric conversion layer
comprises piezoelectric material.
In an exemplary embodiment, the piezoelectric material is zinc
oxide.
An embodiment of the present disclosure further provides a pressure
sensitive touch screen, which comprises a display panel described
in embodiments of the present disclosure.
In an exemplary embodiment, the pressure sensitive touch screen
further comprises pressure sensing units, each of the pressure
sensing units is electrically connected to each of the pressure
sensitive touch structures, wherein each of the pressure sensing
units is configured to determine the magnitude of pressure at the
touch position, by sensing a variation in the magnitude of voltage
between the first touch electrode and the second touch electrode
during the pressure touching stage.
In an exemplary embodiment, each of the pressure sensing units
comprises a pressure sensing circuit and a pressure determining
circuit which correspond to each of the pressure sensitive touch
structures. The pressure sensing circuit is configured to amplify
the voltage of the corresponding pressure sensitive touch structure
and to output the amplified voltage. The pressure determining
circuit is configured to determine the magnitude of pressure at the
touch position according to the voltage output by the pressure
sensing circuit.
In an exemplary embodiment, the pressure sensing circuit comprises
a switch transistor, a first capacitor, and an amplifying
transistor. The switch transistor comprises a gate which is
connected with a reset control terminal, a source which is
connected with a reset signal terminal, and a drain which is
connected with a first terminal of the first capacitor and the
first touch electrode of the corresponding pressure sensitive touch
structure. A second terminal of the first capacitor is connected
with a first reference signal terminal. The amplifying transistor
comprises a gate which is connected with the first terminal of the
first capacitor, a source which is connected with a second
reference signal terminal, and a drain which is connected with the
pressure determining circuit.
In an exemplary embodiment, the pressure sensing circuit comprises
a switch transistor, a first capacitor, and an amplifying
transistor. The switch transistor comprises a gate which is
connected with a reset control terminal, a source which is
connected with a reset signal terminal, and a drain which is
connected with a first terminal of the first capacitor and the
first touch electrode of the corresponding pressure sensitive touch
structure. A second terminal of the first capacitor is connected
with a first reference signal terminal. The amplifying transistor
comprises a gate which is connected with an amplifying control
terminal, a source which is connected with a first terminal of the
first capacitor, and a drain which is connected with the pressure
determining circuit.
In an exemplary embodiment, the pressure sensing circuit further
comprises an amplifier, a second capacitor, and a switch device.
The amplifier comprises a positive phase input terminal which is
connected with a third reference signal terminal, a negative phase
input terminal which is connected with a drain of the amplifying
transistor, and an output terminal which is connected with the
pressure determining circuit. The second capacitor is connected
between the negative phase input terminal and the output terminal
of the amplifier. The switch device is connected between the
negative phase input terminal and the output terminal of the
amplifier.
An embodiment of the present disclosure further provides a display
device, which comprises a pressure sensitive touch screen described
in embodiments of the present disclosure.
Embodiments of the present disclosure provide the display panel,
the pressure sensitive touch screen, and the display device. The
pressure sensitive touch structures are arranged between the array
substrate and the counter substrate. Each of the pressure sensitive
touch structures comprises a first touch electrode, a piezoelectric
conversion layer, and a second touch electrode. In case
piezoelectric material in the piezoelectric conversion layer is
subject to a pressure, positive and negative ions displace
relatively, so that the positive and negative charge center no
longer overlap, and a voltage is developed between a first touch
electrode and a second touch electrode. Therefore, in case the
pressure sensitive touch structures are subject to a pressure, the
pressure sensing units determine the magnitude of pressure at the
touch position by sensing a variation in the magnitude of voltage
between the first touch electrode and the second touch electrode,
thus realizing the function of pressure touching. Since the
pressure sensitive touch structures are embedded in the display
panel, it is only required to make minor modification to the
structural design of the display panel without being limited by the
assembly tolerance, and the detection accuracy is improved.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1a is a structural diagram for illustrating a pressure
sensitive touch screen in an embodiment of the present
disclosure;
FIG. 1b is a structural diagram for illustrating a pressure
sensitive touch screen in an embodiment of the present
disclosure;
FIG. 2a is a structural diagram for illustrating a pressure
sensitive touch screen in an embodiment of the present
disclosure;
FIG. 2b is a structural diagram for illustrating a pressure
sensitive touch screen in an embodiment of the present
disclosure;
FIG. 3a is a structural diagram for illustrating a pressure sensing
circuit in an embodiment of the present disclosure;
FIG. 3b is a structural diagram for illustrating a pressure sensing
circuit in an embodiment of the present disclosure;
FIG. 4a is a structural diagram for illustrating a pressure
sensitive touch screen in an embodiment of the present
disclosure;
FIG. 4b is a structural diagram for illustrating a pressure
sensitive touch screen in an embodiment of the present
disclosure;
FIG. 5a is a structural diagram for illustrating a pressure
sensitive touch screen in an embodiment of the present disclosure;
and
FIG. 5b is a structural diagram for illustrating a pressure
sensitive touch screen in an embodiment of the present
disclosure.
DETAILED DESCRIPTION OF EMBODIMENTS
Specific embodiments of the present disclosure will be further
described hereinafter with reference to the drawings and
embodiments. The following embodiments are only used for explaining
more clearly the technical solution of the present disclosure
rather than limiting the protection scope of the present
disclosure.
The shapes and sizes of components in the drawings are not drawn in
a true scale, and only intend to illustrate the content of the
present disclosure.
As shown in FIGS. 1a-2b, in an embodiment of the present
disclosure, a pressure sensitive touch screen comprises: an array
substrate 1, a counter substrate 2 which is arranged opposite to
the array substrate 1, and a plurality of pixel units 3 which are
arranged in a matrix between the array substrate 1 and the counter
substrate 2. The pressure sensitive touch screen further comprises:
pressure sensitive touch structures 4 which are arranged between
the array substrate 1 and the counter substrate 2, and pressure
sensing units 5 (not shown in FIGS. 1a-2b) which are electrically
connected to the pressure sensitive touch structures 4. Each of the
pressure sensitive touch structures 4 comprises a first touch
electrode 41, a piezoelectric conversion layer 42, and a second
touch electrode 43 which are arranged in this order on a side of
the array substrate 1 facing the counter substrate 2. Each of the
pressure sensing units 5 is configured to determine the magnitude
of pressure at the touch position, by sensing a variation in the
magnitude of voltage between the first touch electrode 41 and the
second touch electrode 43 during the pressure touching stage.
In the above pressure sensitive touch screen, the pressure
sensitive touch structures are arranged between the array substrate
and the counter substrate. Each of the pressure sensitive touch
structures comprises a first touch electrode, a piezoelectric
conversion layer, and a second touch electrode. In case
piezoelectric material in the piezoelectric conversion layer is
subject to a pressure, positive and negative ions displace
relatively, so that the positive and negative charge center no
longer overlap, and a voltage is developed between a first touch
electrode and a second touch electrode. Therefore, in case the
pressure sensitive touch structures are subject to a pressure, the
pressure sensing units determine the magnitude of pressure at the
touch position by sensing a variation in the magnitude of voltage
between the first touch electrode and the second touch electrode,
thus realizing the function of pressure touching. Since the
pressure sensitive touch structures are embedded in the display
panel, it is only required to make minor modification to the
structural design of the display panel without being limited by the
assembly tolerance, and the detection accuracy is improved.
Furthermore, in an embodiment of the present disclosure, the
piezoelectric material is an inorganic piezoelectric material, an
organic piezoelectric material, or a composite piezoelectric
material, and the present disclosure is not limited in this
aspect.
For example, in an embodiment of the present disclosure,
piezoelectric material is zinc oxide, and the present disclosure is
not limited in this aspect.
In implementations, the pressure sensitive touch screen is a liquid
crystal display screen or an organic light emitting display screen,
and the present disclosure is not limited in this aspect.
In particular, in an embodiment of the present disclosure, as shown
in FIGS. 1a-2b, each of the plurality of pixel units 3 comprises a
first conductive layer 31 and a second conductive layer 32 which
are arranged in this order on the array substrate 1.
In an exemplary embodiment, as shown in FIGS. 1a-1b, the first
conductive layer 31 is an anode layer, and the second conductive
layer 32 is a cathode layer. Each of the plurality of pixel units 3
further comprises a light emitting layer 33 which is arranged
between the first conductive layer 31 and the second conductive
layer 32. Namely, the pressure sensitive touch screen described
above is an organic light emitting display screen.
In an alternative embodiment, as shown in FIGS. 2a-2b, the first
conductive layer 31 is a pixel electrode layer, and the second
conductive layer 32 is a common electrode layer. Each of the
plurality of pixel units further comprises an insulating layer 34
which is arranged between the first conductive layer 31 and the
second conductive layer 32. Namely, the pressure sensitive touch
screen described above is a liquid crystal display screen.
For example, in implementations of the pressure sensitive touch
screen, as shown in FIG. 1a and FIG. 2a, the second conductive
layer 32 is multiplexed as the second touch electrode 43, and the
first touch electrode 41 and the first conductive layer 31 are
arranged in a same layer, made from a same material and insulated
from each other. In this way, the second conductive layer 32 is
multiplexed as the second touch electrode 43. Since the first touch
electrode 41 and the first conductive layer 31 are arranged in a
same layer, the process for preparing the first touch electrode 41
and the second touch electrode 43 separately is omitted, which
saves production cost.
In implementations, in an embodiment of the present disclosure, the
pressure sensitive touch screen further comprises a black matrix
which is arranged between the array substrate and the counter
substrate, and an orthographic projection of the first touch
electrode on the array substrate falls within an orthographic
projection of the black matrix on the array substrate. This avoids
effects on the aperture ratio.
For example, in implementations, in an embodiment of the present
disclosure, as shown in FIG. 1b and FIG. 2b, the second touch
electrode 43 and the second conductive layer 32 are arranged in a
same layer, made from a same material and insulated from each
other. In this way, the process for preparing the second touch
electrode separately is omitted, which saves production cost.
In implementations, in an embodiment of the present disclosure, the
pressure sensitive touch screen further comprises a black matrix
which is arranged between the array substrate and the counter
substrate, and an orthographic projection of the black matrix on
the array substrate covers an orthographic projection of the second
touch electrode on the array substrate. This avoids effects on the
aperture ratio.
In implementations, in an embodiment of the present disclosure,
metal electrodes are usually arranged on the array substrate. Of
course, from the view point of simplifying the fabricating process,
it is also possible to arrange the first touch electrode and/or the
second touch electrode in a same layer and form from a same
material as these metal electrodes on the array substrate. The
present disclosure is not limited in this aspect.
Furthermore, in an embodiment of the present disclosure, both the
array substrate and the counter substrate are flexible substrates.
The present disclosure is not limited in this aspect.
Furthermore, in implementations, in an embodiment of the present
disclosure, each of the pressure sensing units comprises: a
pressure sensing circuit and a pressure determining circuit which
correspond to each of the pressure sensitive touch structure in a
one-to-one manner. The pressure sensing circuit is configured to
amplify the voltage of the corresponding pressure sensitive touch
structure and to output the amplified voltage. The pressure
determining circuit is configured to determine the magnitude of
pressure at the touch position according to the voltage which is
output by pressure sensing circuit.
The present disclosure will be described hereinafter in detail with
reference to specific embodiments. It is noted that these
embodiments do not intend to be construed as limitations of the
present disclosure, but to explain the present disclosure.
For example, in an embodiment of the pressure sensitive touch
screen, as shown in FIGS. 3a-3b, each of the pressure sensing units
5 comprises a pressure sensing circuit 51 and a pressure
determining circuit 52. The pressure sensing circuit 51 corresponds
to each of the pressure sensitive touch structures 4 in a
one-to-one manner. The pressure sensing circuit 51 is configured to
amplify a voltage of the corresponding pressure sensitive touch
structures 4 and then output the amplified voltage.
As shown in FIGS. 3a-3b, the pressure sensing circuit 51 comprises:
a switch transistor T1, a first capacitor C1, and an amplifying
transistor T2. The switch transistor T1 comprises a gate which is
connected with a reset control terminal R, a source which is
connected with a reset signal terminal Vint, and a drain which is
connected with a first terminal of the first capacitor C1 and the
first touch electrode 41 of the corresponding pressure sensitive
touch structures 4. A second terminal of the first capacitor C1 is
connected with a first reference signal terminal Vref1.
As shown in FIG. 3a, the amplifying transistor T2 comprises a gate
which is connected with the first terminal of the first capacitor
C1, a source which is connected with a second reference signal
terminal Vref2, and a drain which is connected with the pressure
determining circuit 52. Alternatively, as shown in FIG. 4b, the
amplifying transistor T2 comprises a gate which is connected with
an amplifying control terminal EM, a source which is connected with
the first terminal of the first capacitor C1, and a drain which is
connected with the pressure determining circuit 52.
For example, in order to improve sensing accuracy, in an embodiment
of the pressure sensitive touch screen, as shown in FIG. 3a-FIG.
3b, the pressure sensing circuit 51 further comprises: an amplifier
A, a second capacitor C2, and a switch device K1. The amplifier A
comprises a positive phase input terminal which is connected with a
third reference signal terminal Vref3, a negative phase input
terminal which is connected with the drain of the amplifying
transistor T2, and an output terminal which is connected with the
pressure determining circuit 52. The second capacitor C2 is
connected between the negative phase input terminal and the output
terminal of the amplifier A. The switch device K1 is connected
between the negative phase input terminal and the output terminal
of the amplifier A.
By taking an embodiment shown in FIG. 3a, the operating principle
of the pressure sensing circuit is described. During a first time
period of the pressure touching time period, the reset control
terminal R controls the switch transistor T1 to switch on, a node N
is reset and charged, and the node N has a potential which equals
to the potential of the reset signal terminal Vint. The amplifying
transistor T2 switches on, and supplies the signal of the second
reference signal terminal Vref2 to the negative phase input
terminal of the amplifier, and this signal is amplified by the
amplifier A. It is assumed that the voltage of the output terminal
of the amplifier A, which is received by the pressure determining
circuit 52 at this moment, is V1. When each of the pressure
sensitive touch structures 4 is subject to a pressure, a voltage is
developed between the first touch electrode 41 and the second touch
electrode 43, the potential of the node N changes, and this leads
to a change in the on-state of the amplifying transistor T2. Since
the amplifying transistor T2 is operating in an amplifying state, a
subtle change in the gate voltage will lead to a large current
difference at the drain, and this current difference is further
amplified by the amplifier A. Therefore, the voltage V2 of the
output terminal of the amplifier A, which is received by the
pressure determining circuit 52, will differ significantly from V1.
The pressure determining circuit 52 compares V2 with V1 to obtain a
difference between V1 and V2, and thus determines the magnitude of
pressure.
By taking an embodiment shown in FIG. 3b, the operating principle
of the pressure sensing circuit is described. During a first time
period of the pressure touching time period, the reset control
terminal R controls the switch transistor T1 to switch on, a node N
is reset and charged, and the node N has a potential which equals
to the potential of the reset signal terminal Vint. Under control
of the amplifying control terminal EM, the amplifying transistor T2
switches on and supplies the potential of the node N to the
negative phase input terminal of the amplifier, and this signal is
amplified by the amplifier A. It is assumed that the voltage of the
output terminal of the amplifier A, which is received by the
pressure determining circuit 52 at this moment, is V1. When each of
the pressure sensitive touch structures 4 is subject to a pressure,
a voltage is developed between the first touch electrode 41 and the
second touch electrode 43, the potential of the node N changes, and
this leads to a change in the potential at the source of the
amplifying transistor T2. Since the amplifying transistor T2 is
operating in an amplifying state, a subtle change in the source
voltage will lead to a large current difference at the drain, and
this current difference is further amplified by the amplifier A.
Therefore, the voltage V2 of the output terminal of the amplifier
A, which is received by the pressure determining circuit 52, will
differ significantly from V1. The pressure determining circuit 52
compares V2 with V1 to obtain a difference between V1 and V2, and
thus determines the magnitude of pressure.
A specific configuration of the pressure sensing circuit has been
described in the above embodiment, but the configuration of the
pressure sensing circuit is not limited to the above embodiment.
For example, other configuration known for the ordinary skilled
person in the art is also applicable.
Furthermore, in an embodiment of the pressure sensitive touch
screen, as shown in FIGS. 4a-5b, the array substrate 1 usually is
further provided with a TFT 6 which is connected with the first
conductive layer 31 of each of the plurality of pixel units 3.
Therefore, the switch transistor T1 and the amplifying transistor
T2 of the pressure sensing circuit are also arranged on the array
substrate 1 (only the amplifying transistor T2 is shown in FIGS.
4a-5b). In this way, the switch transistor T1 and the amplifying
transistor T2 of the pressure sensing circuit can be prepared
during preparing other TFTs on the array substrate.
In the above embodiments, the pressure sensitive touch screen
comprises a display panel and pressure sensitive touch structures
which are embedded in the display panel. In an exemplary
embodiment, the pressure sensing units are integrated in the
display panel. In other embodiments, the pressure sensing units and
the display panel are arranged discretely. In case the pressure
sensing units and the display panel are arranged discretely, the
pressure sensitive touch screen shown in FIGS. 1a-1b, 2a-2b, 4a-4b
and 5a-5b actually corresponds to the display panel in embodiments
of the present disclosure.
On basis of a same inventive concept, an embodiment of the present
disclosure further provides a display device, which comprises a
pressure sensitive touch screen in embodiments of the present
disclosure. The display device for example is any product or
component with a display function like a mobile phone, tablet
computer, TV, monitor, notebook computer, digital photo frame, and
navigator. As for embodiments of the display device, reference can
be made to the above embodiments of the pressure sensitive touch
screen.
In the above pressure sensitive touch screen and display device,
the pressure sensitive touch structures are arranged between the
array substrate and the counter substrate. Each of the pressure
sensitive touch structures comprises a first touch electrode, a
piezoelectric conversion layer, and a second touch electrode. In
case piezoelectric material in the piezoelectric conversion layer
is subject to a pressure, positive and negative ions displace
relatively, so that the positive and negative charge center no
longer overlap, and a voltage is developed between a first touch
electrode and a second touch electrode. Therefore, in case the
pressure sensitive touch structures are subject to a pressure, the
pressure sensing units determine the magnitude of pressure at the
touch position by sensing a variation in the magnitude of voltage
between the first touch electrode and the second touch electrode,
thus realizing the function of pressure touching. Since the
pressure sensitive touch structures are embedded in the display
panel, it is only required to make minor modification to the
structural design of the display panel without being limited by the
assembly tolerance, and the detection accuracy is improved.
Apparently, the person with ordinary skill in the art can make
various modifications and variations to the present disclosure
without departing from the spirit and the scope of the present
disclosure. In this way, provided that these modifications and
variations of the present disclosure belong to the scopes of the
claims of the present disclosure and the equivalent technologies
thereof, the present disclosure also intends to encompass these
modifications and variations.
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